Correlation between white blood cell count and neutrophil count after chemotherapy administration at a day hospital

We performed 505 blood analyses corresponding to 259 cancer patients on chemotherapy treatment. We analysed the correlation between absolute leukocyte count (ALC) and absolute neutrophil count (ANC) according to the ECOG scale for myelotoxicity. Our study showed a linear correlation between ALC and ANC. Within this linear regression, important variability was registered in the patients with ALC less than 4000. Thus up to 20% of misclassifications occurred, with the great majority of discrepancies accounted for by a relatively high ANC in relation to the low ALC. Chemotherapy modifications must be based on ANC rather on ALC in order to avoid unnecessary dose reductions and delays of chemotherapy.